Acid pump



Patented Oct. 8, 1935 PATENT Y OFFICE 2,017,026 'ACID PUMP Frank R. Forrest and Frederick I. Lindau, West Allis, Wis., assignors to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application October 28, 19.33, Serial No. 6.95582 y 3 Claims.

This invention relates, in general, to centrifugal pumps, and particularly to centrifugal pumps of the type especially adapted for pumping hot acid liquid, and to a method of dismantling them.

A general object of the invention is to provide a centrifugal pump for pumping hot acid that is of simple and durable construction and that is adapted to be operated and maintained with v minimum attention and labor.

' i centrifugal pump so constructed that it may be dismantled of its rotating element readily and without disturbing the alinement' of the pump casing and the pump driving means.

A more specific object of the invention is to provide a centrifugalpump'n which the rotating element including the shaft ,and its associated parts maybe withdrawn endwise through he pump casing.

Another object of the invention is to provide a method of dismantling and reassembling the rotating element of a centrifugal pump expeditiously and-without disturbing the alinement of its stationary parts.

A further object of the invention is to provide a centrifugal pump having a spiral casing mounted in such manner that it may expand when heated by hot liquid being pumped without causing misalinement of the stationary and rotating elements of the pump.

According to the present invention, a centrifugal pump for pumping hot acid liquids is provided with an impeller of acid resisting metal disposed to operate within a one-piece spiral casing likewise formed of acid resisting metal. The casing is provided at one side with an inlet opening adapted to admit the impeller and at the other side with a shaft opening large enough to accommodate the shaft bearings, coupling and other members carried by the shaft. The shaft opening is normally closed by a stufngfbpx attached to the casing in such manner that it may be removedI inwardly together with'the shaft'and its, associated parts, and withdrawn through the inlet opening of the casing without disturbing the alinement of the pump and is driving element. The one-piece pump casing is so supported on the pump base that it may expand freely from d the heat of hot liquid being pumped,but is restrained from moving out of alinement with the pump impeller.

The foregoing and other objects of the invention may be achieved by the centrifugal pump unit hereinafter described as exemplifying a prac- 5 tical embodiment of the invention and shown in the accompanying drawing, in which: Fig. 1 is a view partly in longitudinal section and partly in side elevation of a centrifugal pump and its driving element mounted on a base; and

Fig. 2 is a fragmentary view partly in end elevation and partly in transverse section taken on the plane representedby the line II-II of Fig. 1.

The illustrated pump unit comprises, in general, a base I that carries in operative alinement a centrifugal pump 2, a bearing supporting pedestal 3 and a driving element 4 which may be an electric motor, as shown, or any other suitable driving mechansm.`

Although the pump 2 may be utilized for pumping liquids of anynature either hot or cold, it is particularly adapted for pumping hot acid liquids. Y To this end it is provided with a spiral casing. 5 of acid resisting metal, preferably chrome steel. 5 As acid liquids have a tendencyto attack sharp corners or projections, especially when ,flowing rapidly past such points, the pump casing 5 is formed in one piece as an integral casting to obviate the necessity of joining separate sections and thus exposing sharp corners to the flowing acid liquid. As shown in Fig. 2, the one-piece spiral casing 5 is provided at. its sides with lugs 6 which rest upon pedestals TI` mounted on the base I, the casing, 4pedestals and base being secured to each 35 other by cap screws 8.

The one-piece casing 5 is provided at one side with an inlet opening 9 Lof diameterlarge enough to admit a pump. runner or impeller I0 that is also formed of acid resisting chrome steel. The 40 pump impeller IIJ is supported in operating position within the casing 5 and in axial alinement therewith upon the end of a pump shaft `I I, which extends through a shaft opening I2 in the side t of the casing opposite from theinlet opening 9. 45'

ends of a bearing housing I5 that encircles the 50 shaft. The bearing housing and bearing are supported in axial alinement with the casing 5 and with the driving element 4 upon the supporting' pedestal 3 to which the vhousing is secured by a bearing cap I5 held' b y cap screws I1. 55 f The bearing housing I5 is disposed as near as 'practicable to the pump impeller III to rigidly side of the impeller I0. A. similar wearing ring 2l on the front or inlet side ofthe impeller is engaged by an inwardly facing bearing surface in an inlet bell or nozzle 22 which constitutes a suction cover. 'I'he inlet nozzle is secured within the inlet opening 9 of the casing 5 by bolts 23 and is adapted to be connected to inlet` piping, usually an elbow section, (not shown) for conducting liquid to the pump.

The driving motor 4 is connected to drive thev pump 2 by means of a coupling element 24 on the motor shaft that is adapted to cooperate with a coupling element 25 mounted on the end of the pump shaft I I and t which itis connected by coupling bolts 26.

In order that the rotating element of the pump may be removed for inspection or repair without disturbing the alinement of the pump casing 5 with the driving motor 4 andthe supporting pedestal 2, the shaft opening I2 of the casing is made sufficiently large to accommodate the bearing housing I5 and the coupling element 25. To permit withdrawal of the shaft with its bearing housing and coupling element through the shaft opening I2, the stuiilng box land the stuiling box bushing I9 are secured against the inner surface of the casing 5 by bolts 21 in such manner them to be withdrawn inwardly with the shaft I I through the inlet opening 9 of the casing.

.In dismantling the pump unit of its rotating element, the suction pipe elbow or other suction connection is'rst disconnected from the inlet nozzle 22, after which the inlet nozzle may be,` removed from the inlet opening 9 and the impeller I0 unfastened from the shaft lII by unscrewing an impeller retaining screw 28 which is threaded into the end of the shaft. After the impeller I0 has been unfastened, it is withdrawn from the casing through the inlet opening 9. The shaft II is then released for removal by removing the coupling bolts 26 to disconnect the coupling element 25 from the motor 4, withdrawing the cap screws I1 and removing the bearing cap I5 Lfrom the bearing housing I5 and then withdrawing the bolts 2l to release the stumng box I8 from opening 9 and the shaft opening I2 into operating position.l The bearing housing and the stuiiing box arethen secured to their respective supporting elements andthe coupling element 25 joined to the coupling element 24 of the motor. The

'pump impeller I0 is then inserted throughl ythe `inlet opening 9 and attached to the end of the shaft by the screw 28 after which the inlet nozzle 22 is secured in the ilet .opening and the inlet piping connected to it.

When the pump is utilized for pumping liquid heated above atmospheric temperature, the solid 5 pump casing 5 expands -in proportion to the temperature ofthe liquid being pumped.Y To permit the casing 5 to expand freely without disturing its cooperating relationship with the rotating impeller IIL'its supporting lugs 6 and the supporting pedestals I are so positioned'that the casing is supported upon the pedestals only at points lying in a horizontal plane passing through the alined axes of the pump casing and the pump impeller. 'This arrangement'of supports permits the pump 15 casing 5 to expand upward and downward from` the plane of support without causing vertical movement of the pump casing axis relative to the pump impelleraxis. To prevent 'horizontal movement of the casing), axis relative to the impeller 20 axis, the pump is provided with acasing key block 29 disposed to engage the casing v`beneath the shaft opening I 2 in the vertical longitudinal plane of the pump. As shown in Fig. 2 the key block 29 slidingly engages the sides of a rectangular seat 2?, 30 in the casing 5 and is fitted in a similar alined rectangular seat 3| ,in the bearing supporting pedestal 3 in such manner that the casing 5 may move vertically relative to the pedestal 3 but is restrained from horizontal movement relative39f thereto to prevent horizontal movement of the casing axis relative to the axis of the rotating impeller I0. l

The pumping unit herein described is particu-c larly well adapted for pumping hot acid liquids in that it is provided with a one-piece pump c as- Ving and a cooperating impeller both formed of acid resisting material, the casing being so mounted that expansion thereof from the heat of the liquid being pumped does not result in misaline- 4Q@ ment of the cooperating pump parts. The operations of dismantling and reassembling the pump are greatly .facilitated by the arrangement of the casing openings in such manner. that the parts' making up the rotating element of the pump may 45 described in detail to' fully disclose a working 50;,

embodiment of the invention, it is to be imderstood that the structure shown and described herein may be modied without departing from the spirit and scope of the invention as defined in the subjoined claims. Y f

It is claimed and desired to seclne by Letters Patent: y

1. A centrifugal pump assembly, comprising a base, a bearing pedestal carried by said base, a

bearing housing carried by said bearing pedestal, tio--4 a shaft journaled in said bearing housing, a driving element m'ounted on said base in andai alinement with said shaft, a coupling joining said driving element to said shaft, a pump impeller carried byV said shaft, a one-piece spiral pump sa casing mounted in axial alinement with said bear-V ing pedestal and said driving element on said base in position to enclose said impeller and having an inlet opening adapted to admit said impeller and an alined shaft opening adapted to 73'.

' admit said bearing housing and said shaft 'coupling, and a stuiling box engaging' said shaft mounted in said casing in position to close .said shaft opening and secured in such manner as to be removable therefrom through said inlet open- "i ing; whereby said stumng box, together with said shaft, said bearing housing, and said coupling may be withdrawn vthrough said inlet opening without disturbing the relative positions of said casing, said driving element, or s aid bearing pedestal. a

2. A centrifugal pump for pumping hot acid, comprising a base, a bearing pedestal carried by said base, abearing housing carried by said bearing pedestal, a shaft journaled in said bearing housing, a driving element mounted on said base in axial alinementwith said shaft, a coupling disposed to connect said driving element to said shaft, an acid'resisting chrome steel pump impeller carried by said shaft, a one-piece acid resisting chrome steel spiral pump casing disposed to enclose and cooperate with said impeller and supported upon said base solely at points lying in a horizontal plane through the axis of said shaft, said casing having an inlet opening adapted to admit said impeller and a shaft opening alined therewith and adapted to admit said bearing housing and said coupling, a stuiiing box on said shaft secured within said casing to close said shaft opening and removable through said inlet opening to permit withdrawing saidvshaft with its bearings and coupling through said opening, and means on said casing slidably engaging said base to prevent movement of the axis of said casing along its plane of support while permitting expansion of said casing under the iniiuence of the hot acid being pumped to maintain said casing in concentric relation with said impeller.

3. A pumping unit for pumping hot acid comf prising a spiral pump casing formed in one piece of acid resisting metal and having opposed inlet and shaft openings, a base disposed to support said casing only at points in a horizontal axial plane thereof, a pump impeller of acid resisting metal disposed within said casing in coaxial cooperating relation therewith and i0.

adapted to be withdrawn through said inlet open- `ing, a shaft attached to said impeller for supporting and driving it and extending through said shaft opening, a bearing-housing adapted topass through said shaft opening and said inlet openlliV ing carried by said shaft and detachably secured to said base in position to rotatably support said shaft and said impeller in operating relation to said casing, a stumng box surrounding said shaft in position to close'said shaft opening in said casing and adapted to be withdrawn with said shaft through said inlet opening, a driving element mounted on said base, and a' coupling disposed to connect said driving element to said shaft and adapted to be withdrawn with said shaftA and said bearing housing through said shaft opening and said inlet opening of said casing.

FRANK R. FORREST.

FREDERICK I. LINDAU. 

